ARRL Logbook of the WorldA repository of log records submitted by
users from around the world; when both participants in a
QSO submit matching QSO records to LoTW, the QSO can be used for ARRL
award credit

The Art and Skill of
Radio-Telegraphy by N0HFF An in-depth manual for learning, using,
mastering and enjoying the international morse code as a means of
communication. 3rd edition, provided in Adobe Acrobat and MS Word
formats